I know when become less than 109.5° angle will cause angle strain that will reduce the stability of compound but why? ( I mean what is the reason decrease the stability of compound or what is the factor that affected on stability when decreases the angle?) Is it because steric hindrance? Or what?

  • $\begingroup$ In VSEPR it is assumed that the bond distribution (the angles between bonds) is due to minimization of electron repulsion. $\endgroup$
    – Buck Thorn
    Commented May 19 at 11:59
  • $\begingroup$ Your previous question was closed and this is just a duplicate of that question. Try editing the previous question to (hopefully) have it reopened rather than reposting a question that was closed. This will lead most likely to an eventual question ban on your account. $\endgroup$
    – Buck Thorn
    Commented May 19 at 12:00